Video and audio source material editing systems employing digital techniques have been introduced over the last several years. One example is the Avid/1 Media Composer from Avid Technology, Inc., of Burlington, Massachusetts. This media composer receives, digitizes, stores and edits video and audio source material. After the source material is digitized and stored, a computer such as an Apple MacIntosh based computer manipulates the stored digital material and a pair of CRT monitors are used for displaying manipulated material and control information to allow editing to be performed. Later versions of the media composer included compression techniques to permit the display of full motion video from the digitized source material. Compression was achieved using a JPEG chip from C-Cube of Milpitas, Calif. That data compression is described more fully in copending application U.S. Ser. No. 07/807,269 filed Dec. 13, 1991, and entitled Buffer and Frame Indexing. The teachings of this application are incorporated herein by reference. Although previous media composers could achieve full motion video from digitized sources, the compression degraded image quality below desirable levels. Further, the media composer lacked features which enhance the editing process.
The media composer according to the invention for editing source material includes apparatus for receiving, digitizing, storing and editing video and audio source material. Computing apparatus manipulates the stored source material and output apparatus communicates with the computing apparatus for displaying the manipulated material and control information. The computing apparatus includes JPEG compression apparatus and is programmed so that multiple JPEG resolutions can be displayed, recorded and played back.
In another aspect of the invention, the computing apparatus is programmed to provide motion effects in the displayed material and is further programmed to provide a dial whose rotation rate corresponds to a selected motion effect rate. Motion effects include forward and reverse variable speed effects, fit-to-fill capability, and strobe motion. The improved media composer of the invention enables a variety of wipes to be effected, zoom to fill screen capability, pitch change audio scrub, graphics positioning and image capture instrumentation The system also enables sync point editing and slip sync. The system also provides for a novel mechanical user interface including a track ball and speed control integrated into a single unit. Importantly, the system also supports a media consolidation process to free up disk space.